AC water condensation on passenger side

[HBlue]

I don't think this is a water backup.

Several times in the past water has dripped on the passenger side.

Last week I found out my evaporator core housing was damaged and did not seal at the bottom. There was a 3/8 gap and the bottom screws would not tighten. I lost a a lot of cold air and the water was draining out the opening. I found the right side housing in a salvage yard replaced it. I made sure the door diverting air to the heater worked properly.

Today on a test run the AC was freezing me out. The air flow I was getting with the blower on 4, I am now getting with it on 2. And water began dripping again.

I could not find any leaks, but I did find the back of the heater housing was very cold and very wet from condensation. I think the condensed water was dripping off the housing onto the floor.

I would appreciate any suggestions.

This is on a '76 C-10.
thanks